1. Field of the Invention
The present invention involves a returnable framework structure capable of being easily assembled and disassembled, and more particularly to a returnable framework structure for enclosing loads and transporting packaged freight. The returnable framework structure is returned, after being evacuated and disassembled, to the site of reloading to be reused after being reassembled.
2. Brief Description of the Prior Art
An example of a returnable structure, shown in FIG. 18 as an exploded perspective view, includes a skid 70 forming a bottom, support frames 71 disposed in front and rear of the skid 70, and side frames 72 on left and right sides. A top frame 74 connects the side of the frames. The structure is assembled with frames which are tightened by means of bolts at a packaging site.
When conventional returnable structures are returned in a container or the like, each component can not be enclosed in compact form, and therefore it is difficult to return a number of structures without occupying a large space. Also, nuts to be fastened with bolts are welded on each retaining position. As each frame is tightened by bolts, a period of time and labor are inevitably required for setting and removing a necessary number of bolts. This operation can not be performed by a single person.
Also, in conventional structures the stability of a number of returnable structures stacked upon each other is not always satisfactory.